Hyperthyroidism is not a typically associated with pancreatitis. There have been rare reports of pancreatitis due to tapazole or PTU. Elevated blood calcium (sometimes seen in hyperthyroidism) can also contribute to pancreatitis.
There are other more common causes --- gallstones, alcohol use, high triglycerides, etc.
In some rare cases other auto-immune diseases (assuming Graves is the cause of your hyperthyroidism) may be associated with pancreatitis.